1. Field of the Invention
The present invention relates to a socket interposed between paths through which compressed air flows, and to a pipe fitting including the socket.
2. Description of the Related Art
Generally, an air compressor for supplying compressed air to a nail gun which is driven by compressed air is provided with a socket at its air supply port, and a plug is provided to one end portion of a hose connected to the socket at the air supply port. Moreover, a socket is provided to the other end portion of the hose, and an air tool driven by compressed air such as a nail gun is provided with a plug at a portion connected to the socket at the other end portion of the hose. By inserting and fixing the sockets to the plugs to connect each part, compressed air can be supplied into the hose through the air supply port of the air compressor. Common sockets and plugs are described for instance in Japanese Patent Application Publication No. 2000-55272.
Meanwhile, for easy detachment of a socket and a plug, a fitting has been developed which allows detachment of these two parts by using the pressure of a manual pressing-down action (this technology is described for instance in Published Japanese Translation of PCT International Application No. 2008-531947, and Japanese Patent Application Publication No. 2005-207591). Hereinbelow, a pipe fitting capable of detachment of a socket and a plug via the pressing down of a predetermined portion will be referred to as a “pressing-type pipe fitting.”
Referring to FIG. 3 and [0016] of Published Japanese Translation of PCT International Application No. 2008-531947, a mechanism 18 is incorporated in a female element 7, and this mechanism 18 serves to fix a plug 5. Specifically, the plug 5 is fixed at a predetermined portion inside a housing 9 by a spring 19, a latch 20, and a driving member 21 provided to the mechanism 18. Further, by pressing down the mechanism 18, this fixed state is released, so that the fit of the plug 5 and the housing 9 is released.
Referring to FIG. 1, [0017], and [0018] of Japanese Patent Application Publication No. 2005-207591, a lock 4 is slidably incorporated in a housing part, and this lock 4 fixes a plug to a socket. Also, referring to FIG. 7 and [0033] to [0035], the plug can be pulled out when the member 42 is moved down.
However, in the case of the above socket members described in Published Japanese Translation of PCT International Application No. 2008-531947 and Japanese Patent Application Publication No. 2005-207591, the plug may not be easily fit into an inserted state in some cases.
For example, referring to FIG. 1 of Published Japanese Translation of PCT International Application No. 2008-531947, a collar 6 of the plug 5 is brought into engagement with a tooth 32 of the socket to thereby set the plug in an inserted state inside the socket. However, if the engaging side surface of the collar 6 is an inclined surface, good engagement may not be realized. The same problem occurs also to the invention described in Japanese Patent Application Publication No. 2005-207591.